This illuminated 40mm mushroom shape push button head for integral LED is part of of the range diameter 22mm, Harmony XB4.It is ideal when quick actions are required.It fits for a process or machine to function correctly or where operator movements require highest ergonomy.It is easily combined with Harmony range of contact blocks to perform a large variety of control functions.It is clearly distinguishable visually at a distance thanks to its illuminated head.It is impact resistant, dust resistant, water resistant and vibration resistant thanks to its IP66.It makes it ideal for operation in harsh environments.